New research suggests that from the 2030s onwards man-made climate change will significantly reduce crop yield in temperate and tropical regions.
"Our research shows that crop yields will be negatively affected by climate change much earlier than expected," Professor Andy Challinor, from the School of Earth and Environment at the University of Leeds and lead author of the study, said in a news release. "Furthermore, the impact of climate change on crops will vary both from year-to-year and from place-to-place - with the variability becoming greater as the weather becomes increasingly erratic."
The researchers created a new data set by looking at 1,700 published assessments on how climate change will affect rice, maize and wheat crops. The team was able to gather the largest-ever dataset on crop responses.
In the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report researchers reported that regions such as Europe and the majority of North America would be able to deal with a few degrees of warming without seeing it affect seasonal harvests. These new findings will be incorporated into the panel's fifth report set to be published in the near future.
"As more data have become available, we've seen a shift in consensus, telling us that the impacts of climate change in temperate regions will happen sooner rather than later," Professor Challinor said.
The research team concluded the world would see crop consequences after a warming of only two degrees Celsius, or by the 2030s. In the second half of the century decreases of over 25 percent could be even more common.
In some regions farmers have already been forced to adjust their planting dates or crop variety in order to adapt to warming temperatures.
"Climate change means a less predictable harvest, with different countries winning and losing in different years. The overall picture remains negative, and we are now starting to see how research can support adaptation by avoiding the worse impacts," Professor Challinor said.
